DOCSLIB.ORG

2019.12.23.887182V1.Full.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
2019.12.23.887182V1.Full.Pdf bioRxiv preprint doi: https://doi.org/10.1101/2019.12.23.887182; this version posted December 23, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Two distinct bacterial biofilm components trigger 2 metamorphosis in the colonial hydrozoan Hydractinia echinata 3 4 Huijuan Guo,1# Maja Rischer,1# Martin Westermann,2 Christine Beemelmanns1,* 5 1 Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, 6 Beutenbergstraße 11a, D-07745 Jena, Germany 7 2 Electron Microscopy Centre, Friedrich Schiller University Jena, Ziegelmühlenweg 1, D-07743 8 Jena, Germany 9 # contributed equally 10 * Email: [email protected] (ORCID 0000-0002-9747-3423) 11 12 Classification 13 Major: Chemical Sciences 14 Minor: Ecology 15 Keywords 16 Hydractinia, Pseudoalteromonas, metamorphosis, phospholipids, polysaccharides 17 Author Contributions 18 Conceptualization: M.R, H.G, M.W., C.B.; Methodology: M.R, H.G, M.W., C.B.; Investigations: 19 M.R, H.G, M.W., C.B.; Resources: M.W., C.B.; Writing – Original Draft: M.R, H.G, C.B. 20 Supervision and Funding Acquisition: M.W., C.B. 21 This PDF file includes: 22 Main Text 23 Figures 1 to 6 24 1 bioRxiv preprint doi: https://doi.org/10.1101/2019.12.23.887182; this version posted December 23, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Abstract 2 Bacterial-induced metamorphosis of larvae is a widespread cross-kingdom communication 3 phenomenon within the marine environment and critical for the persistence of many invertebrate 4 populations. However, the chemical structures of the majority of inducing bacterial signals and the 5 underlying cellular mechanisms remain enigmatic. Hydractinia echinata larvae transform upon 6 detection of bacterial biofilm components into the colonial adult stage. Despite serving as cell 7 biological model system for decades, the inducing bacterial signals remained undiscovered. 8 Using a chemical-ecology driven analysis, we herein identified that specific bacterial 9 (lyso)phospholipids and polysaccharides, naturally present in bacterial biofilms, elicit 10 metamorphosis in Hydractinia larvae. While (lyso)phospholipids (e.g. 16:0LPG/18:1LPE, 16:0 11 LPA/18:1LPE) as single compounds or in combinations induced up to 50% of all larvae to 12 transform within 48 h, two structurally distinct polysaccharides, the newly identified Rha-Man 13 polysaccharide from Pseudoalteromonas sp. P1-9 and curdlan from Alcaligenes faecalis caused 14 up to 75% of all larvae to transform within 24 h. We also found combinations of 15 (lyso)phospholipids and curdlan induced the transformation in almost all larvae within 24 h, 16 thereby exceeding the morphogenic activity observed for single compounds and axenic bacterial 17 biofilms. By using fluorescence-labeled bacterial phospholipids, we demonstrated their 18 incorporation into the larval membranes, where interactions with internal signaling cascades 19 could occur. Our results demonstrate that multiple and structurally distinct bacterial-derived 20 metabolites converge to induce high transformation rates of Hydractinia larvae, which might 21 ensure optimal habitat selection despite the general widespread occurrence of both compound 22 classes. 23 24 Significance Statement 25 Bacterial biofilms profoundly influence the recruitment and settlement of marine invertebrates, 26 critical steps for diverse marine processes such as coral reef formation, marine fisheries and the 27 fouling of submerged surfaces. Yet, the complex composition of biofilms often makes it 28 challenging to characterize the individual signals and regulatory mechanisms. Developing 29 tractable model systems to characterize these ancient co-evolved interactions is the key to 30 understand fundamental processes in evolutionary biology. Here, we characterized for the first 31 time two types of bacterial signaling molecules that induce the morphogenic transition and 32 analyzed their abundance and combinatorial activity. This study highlights the crucial role of the 33 converging activity of multiple bacterial signals in development-related cross-kingdom signaling. 34 35 36 2 bioRxiv preprint doi: https://doi.org/10.1101/2019.12.23.887182; this version posted December 23, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Main Text 2 3 Introduction 4 The radical transformation (metamorphosis) of planula larvae into the adult stage is a critical step 5 in the life cycle of many marine species as it confers the propagation and persistence of the 6 population in the marine ecosystem.1 For more than 80 years it has been recognized that 7 chemical signals present within marine bacterial biofilms induce or even prevent settlement and 8 metamorphosis in benthic marine larvae,2-4 but their identification remains still a challenging task 9 due to low production levels and unestablished model systems. Hence, until today only very few 10 key bacterial signals have been structurally characterized.5-7 A prime example represents the 11 bacterial product thallusin isolated from Zobellia uliginosa, which induces metamorphosis in the 12 alga Monostroma oxyspermum.8 Several members of the Polychaeta class and Cnidaria phylum 13 have also served as model systems for bacterial-induced metamorphosis over decades.9,10 In 14 several studies, it was found that bromopyrroles produced by Pseudoalteromonas induce larvae 15 of several coral species to undergo metamorphosis; however induced larvae failed to attach to 16 surfaces when stimulated by bromopyrroles alone indicating that other, yet unidentified, chemical 17 cues might be important for the morphogenic process.11,12 Recent biochemical investigations of 18 the bacteria-induced metamorphosis of the marine polychaete Hydroides elegans resulted in the 19 identification of a phage tail-like contractile injection systems (tailocins) in Pseudoalteromonas 20 species that induce settlement and metamorphosis by releasing an effector protein Mif1, which 21 stimulates the P38 and MAPK signaling pathways.13-15 However, bacteria not capable of 22 producing theses proteinaceous injection systems were also found to induce the transformation 23 releasing additional, yet structurally not defined morphogens.16,17 In the 1970s, Leitz and Wagner 24 reported that a lipid-like molecule of Pseudoalteromonas espejiana (original name: Alteromonas 25 espejiana) induces larvae transformation in Hydractinia echinata, an early branching metazoan 26 lineage dating back more than 500 million years.18,19 But despite intensive studies, the bacterial 27 signals causing Hydractinia larvae to metamorphose have remained elusive. Instead, 28 metamorphosis of Hydractinia was artificially induced using high salt concentrations (CsCl) 29 allowing seminal studies on migratory stem cells, allorecognition (self-recognition), the canonical 30 Wnt-signalling system, and the development of muscles and nervous systems.20,21 However, it 31 was noted from early on that artificial induction caused phenotypical and developmental 32 differences in Hydractinia development compared to bacterial induction.22 33 34 The long-standing unsolved question about the structures of bacterial signals and the apparent 35 morphological differences in larvae development between artificial and natural induction attracted 36 our interest. Thus, we set out to solve the structures of the bacterial signals that induce 37 metamorphosis in Hydractinia, which would allow us to shed light on the biochemistry underlying 38 this ancient prokaryote-eukaryote signaling mechanisms.23 39 3 bioRxiv preprint doi: https://doi.org/10.1101/2019.12.23.887182; this version posted December 23, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Results 2 Bioassay-guided identification of bacterial signals 3 To investigate which co-occurring bacteria induce metamorphosis in H. echinata (hereafter 4 Hydractinia) we isolated morphological distinct co-occurring bacterial species from the surface of 5 a healthy and freshly collected Hydractinia colony.24 For a mono-species biofilm-based 6 metamorphosis assay, we selected 29 representative bacterial isolates, including seven genome- 7 sequenced Hydractinia-associated strains, one coral associated strain Pseudoalteromonas sp. 8 PS5,11,12 and eight bacterial type strains obtained from culture collections. Similar to previous 9 observations, we observed the inconsistent timing of metamorphosis using biofilms compared to 10 the artificial control (> 6 mM CsCl final concentration), presumably due the inhomogeneous 11 nature of biofilms and spatial concentrations differences of the yet unidentified inducing signals in 12 bacterial biofilms. To enable a comparative analysis of the inducing activity, we adopted the 13 established stage-chart of morphological appearances by Leitz
Load more

Recommended publications
  • Diverse Deep-Sea Anglerfishes Share a Genetically Reduced Luminous
    RESEARCH ARTICLE Diverse deep-sea anglerfishes share a genetically reduced luminous symbiont that is acquired from the environment Lydia J Baker1*, Lindsay L Freed2, Cole G Easson2,3, Jose V Lopez2, Dante´ Fenolio4, Tracey T Sutton2, Spencer V Nyholm5, Tory A Hendry1* 1Department of Microbiology, Cornell University, New York, United States; 2Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Fort Lauderdale, United States; 3Department of Biology, Middle Tennessee State University, Murfreesboro, United States; 4Center for Conservation and Research, San Antonio Zoo, San Antonio, United States; 5Department of Molecular and Cell Biology, University of Connecticut, Storrs, United States Abstract Deep-sea anglerfishes are relatively abundant and diverse, but their luminescent bacterial symbionts remain enigmatic. The genomes of two symbiont species have qualities common to vertically transmitted, host-dependent bacteria. However, a number of traits suggest that these symbionts may be environmentally acquired. To determine how anglerfish symbionts are transmitted, we analyzed bacteria-host codivergence across six diverse anglerfish genera. Most of the anglerfish species surveyed shared a common species of symbiont. Only one other symbiont species was found, which had a specific relationship with one anglerfish species, Cryptopsaras couesii. Host and symbiont phylogenies lacked congruence, and there was no statistical support for codivergence broadly. We also recovered symbiont-specific gene sequences from water collected near hosts, suggesting environmental persistence of symbionts. Based on these results we conclude that diverse anglerfishes share symbionts that are acquired from the environment, and *For correspondence: that these bacteria have undergone extreme genome reduction although they are not vertically [email protected] (LJB); transmitted.
    [Show full text]
  • Bioactive Compounds of Pseudoalteromonas Sp. IBRL PD4.8 Inhibit Growth of Fouling Bacteria and Attenuate Biofilms of Vibrio Alginolyticus FB3
    Polish Journal of Microbiology ORIGINAL PAPER 2019, Article in Press https://doi.org/10.21307/pjm-2019-003 Bioactive Compounds of Pseudoalteromonas sp. IBRL PD4.8 Inhibit Growth of Fouling Bacteria and Attenuate Biofilms of Vibrio alginolyticus FB3 NOR AFIFAH SUPARDY1*, DARAH IBRAHIM1, SHARIFAH RADZIAH MAT NOR1 and WAN NORHANA MD NOORDIN2 1 Industrial Biotechnology Research Laboratory (IBRL), School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia 2 Fisheries Research Institute (FRI), Penang, Malaysia Submitted 12 August 2018, revised 11 October 2018, accepted 29 October 2018 Abstract Biofouling is a phenomenon that describes the fouling organisms attached to man-made surfaces immersed in water over a period of time. It has emerged as a chronic problem to the oceanic industries, especially the shipping and aquaculture fields. The metal-containing coatings that have been used for many years to prevent and destroy biofouling are damaging to the ocean and many organisms. Therefore, this calls for the critical need of natural product-based antifoulants as a substitute for its toxic counterparts. In this study, the antibacte- rial and antibiofilm activities of the bioactive compounds of Pseudoalteromonas sp. IBRL PD4.8 have been investigated against selected fouling bacteria. The crude extract has shown strong antibacterial activity against five fouling bacteria, with inhibition zones ranging from 9.8 to 13.7 mm and minimal inhibitory concentrations of 0.13 to 8.0 mg/ml. Meanwhile, the antibiofilm study has indicated that the extract has attenuated the initial and pre-formed biofilms of Vibrio alginolyticus FB3 by 45.37 ± 4.88% and 29.85 ± 2.56%, respectively.
    [Show full text]
  • Biotechnological Potential of Cold Adapted Pseudoalteromonas Spp
    marine drugs Article Biotechnological Potential of Cold Adapted Pseudoalteromonas spp. Isolated from ‘Deep Sea’ Sponges Erik Borchert 1, Stephen Knobloch 2, Emilie Dwyer 1, Sinéad Flynn 1, Stephen A. Jackson 1, Ragnar Jóhannsson 2, Viggó T. Marteinsson 2, Fergal O’Gara 1,3,4 and Alan D. W. Dobson 1,* 1 School of Microbiology, University College Cork, National University of Ireland, Cork T12 YN60, Ireland; [email protected] (E.B.); [email protected] (E.D.); [email protected] (S.F.); [email protected] (S.A.J.); [email protected] (F.O.) 2 Department of Research and Innovation, Matís ohf., Reykjavik 113, Iceland; [email protected] (S.K.); [email protected] (R.J.); [email protected] (V.T.M.) 3 Biomerit Research Centre, University College Cork, National University of Ireland, Cork T12 YN60, Ireland 4 School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth 6102, WA, Australia * Correspondence: [email protected]; Tel.: +353-21-490-2743 Received: 22 February 2017; Accepted: 14 June 2017; Published: 19 June 2017 Abstract: The marine genus Pseudoalteromonas is known for its versatile biotechnological potential with respect to the production of antimicrobials and enzymes of industrial interest. We have sequenced the genomes of three Pseudoalteromonas sp. strains isolated from different deep sea sponges on the Illumina MiSeq platform. The isolates have been screened for various industrially important enzymes and comparative genomics has been applied to investigate potential relationships between the isolates and their host organisms, while comparing them to free-living Pseudoalteromonas spp. from shallow and deep sea environments.
    [Show full text]
  • Aquatic Microbial Ecology 80:15
    The following supplement accompanies the article Isolates as models to study bacterial ecophysiology and biogeochemistry Åke Hagström*, Farooq Azam, Carlo Berg, Ulla Li Zweifel *Corresponding author: [email protected] Aquatic Microbial Ecology 80: 15–27 (2017) Supplementary Materials & Methods The bacteria characterized in this study were collected from sites at three different sea areas; the Northern Baltic Sea (63°30’N, 19°48’E), Northwest Mediterranean Sea (43°41'N, 7°19'E) and Southern California Bight (32°53'N, 117°15'W). Seawater was spread onto Zobell agar plates or marine agar plates (DIFCO) and incubated at in situ temperature. Colonies were picked and plate- purified before being frozen in liquid medium with 20% glycerol. The collection represents aerobic heterotrophic bacteria from pelagic waters. Bacteria were grown in media according to their physiological needs of salinity. Isolates from the Baltic Sea were grown on Zobell media (ZoBELL, 1941) (800 ml filtered seawater from the Baltic, 200 ml Milli-Q water, 5g Bacto-peptone, 1g Bacto-yeast extract). Isolates from the Mediterranean Sea and the Southern California Bight were grown on marine agar or marine broth (DIFCO laboratories). The optimal temperature for growth was determined by growing each isolate in 4ml of appropriate media at 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50o C with gentle shaking. Growth was measured by an increase in absorbance at 550nm. Statistical analyses The influence of temperature, geographical origin and taxonomic affiliation on growth rates was assessed by a two-way analysis of variance (ANOVA) in R (http://www.r-project.org/) and the “car” package.
    [Show full text]
  • Antagonistic Activity of Marine Bacteria Pseudoalteromonas Tunicata Against Microbial Pathogens
    African Journal of Microbiology Research Vol. 5(5) pp 562-567, 4 March, 2011 Available online http://www.academicjournals.org/ajmr DOI: 10.5897/AJMR10.103 ISSN 1996-0808 ©2011 Academic Journals Full Length Research Paper Antagonistic activity of marine bacteria Pseudoalteromonas tunicata against microbial pathogens Sivasubramanian K1*, Ravichandran S1 and Vijayapriya M2 1Center of Advance Study in Marine biology, Annamalai University, Parangipetti-608 502, India. 2Department of Microbiology, Annamalai University, Annamalainagar-608002, Tamilnadu, India. Accepted 28 March, 2011 Marine bacteria have been recognized as an important and untapped resource for novel bioactive compounds. In the present study the antagonistic activity of marine bacteria was investigated. The selected Pseudoalteromonas tunicata showed a very broad range of antagonistic activity against many pathogenic bacteria and fungi. The antagonistic strains were also tested for the production of exo-enzymatic activities, 83% of the selected marine bacterial strains produced proteases except Pseudoalteromonas denitificans and Pseudoalteromonas piscicida. Lipase activity was produced by Pseudoalteromonas aliena, Pseudoalteromonas aurantia, Pseudoalteromonas tunicata and Pseudoalteromonas citrea strains. The P. tunicata strain isolated in the present study seems to have potential antifungal and antimicrobial activity against most of the human bacterial pathogens and phytopathogenic fungi. Thus, the marine bacterial strain P. tunicata was having the potential of producing bioactive
    [Show full text]
  • Bioactivity, Chemical Profiling, and 16S Rrna-Based Phylogeny of Pseudoalteromonas Strains Collected on a Global Research Cruise
    Downloaded from orbit.dtu.dk on: Oct 04, 2021 Bioactivity, Chemical Profiling, and 16S rRNA-Based Phylogeny of Pseudoalteromonas Strains Collected on a Global Research Cruise Vynne, Nikolaj Grønnegaard; Månsson, Maria; Nielsen, Kristian Fog; Gram, Lone Published in: Marine Biotechnology Link to article, DOI: 10.1007/s10126-011-9369-4 Publication date: 2011 Link back to DTU Orbit Citation (APA): Vynne, N. G., Månsson, M., Nielsen, K. F., & Gram, L. (2011). Bioactivity, Chemical Profiling, and 16S rRNA- Based Phylogeny of Pseudoalteromonas Strains Collected on a Global Research Cruise. Marine Biotechnology, 13(6), 1062-1073. https://doi.org/10.1007/s10126-011-9369-4 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. 1 Bioactivity, chemical profiling and 16S rRNA based phylogeny of 2 Pseudoalteromonas strains collected on a global research cruise 3 4 Nikolaj G. Vynne1*, Maria Månsson2, Kristian F. Nielsen2 and Lone Gram1 5 6 1 Technical University of Denmark, National Food Institute, Søltofts Plads, bldg.
    [Show full text]
  • Pseudoalteromonas Maricaloris Sp. Nov., Isolated from an Australian Sponge, and Reclassification Of
    International Journal of Systematic and Evolutionary Microbiology (2002), 52, 263–271 Printed in Great Britain Pseudoalteromonas maricaloris sp. nov., NOTE isolated from an Australian sponge, and reclassification of [Pseudoalteromonas aurantia] NCIMB 2033 as Pseudoalteromonas flavipulchra sp. nov. 1 Pacific Institute of Elena P. Ivanova,1† Ludmila S. Shevchenko,1 Tomoo Sawabe,2 Bioorganic Chemistry of 3 4 1 the Far-Eastern Branch of Anatolii M. Lysenko, Vasilii I. Svetashev, Nataliya M. Gorshkova, the Russian Academy of Masataka Satomi,5 Richard Christen6 and Valery V. Mikhailov1 Sciences, 690022 Vladivostok, pr. 100 Let Vladivostoku 159, Russia Author for correspondence: Elena P. Ivanova. Tel: j61 3 9214 5137. Fax: j61 3 9214 5050. 2 Laboratory of e-mail: eivanova!groupwise.swin.edu.au Microbiology, Faculty of Fisheries, Hokkaido University, 3-1-1 Minato- A marine, Gram-negative, aerobic bacterium that produced cytotoxic, lemon- cho, Hakodate 041-8611, yellow, chromopeptide pigments that inhibited the development of sea urchin Japan eggs has been isolated from the Australian sponge Fascaplysinopsis reticulata 3 Institute of Microbiology Hentschel. The cells of the organism were rod-shaped with a single polar of the Russian Academy of Sciences, 117811 Moscow, flagellum and they required NaCl for growth (05–10%) with optimum growth Russia at 1–3% NaCl. The temperature for growth was 10–37 SC, with optimum growth 4 Institute of Marine Biology at 25–30 SC. Growth occurred at pH values from 60to100, with optimum of the Far-Eastern Branch growth at pH 60–80. Major phospholipids were phosphatidylethanolamine, of the Russian Academy of phosphatidylglycerol and lyso-phosphatidylethanolamine. Of 26 fatty acids Sciences, 690041 Vladivostok, Russia with 11–19 carbon atoms that were detected, 16:1ω7, 16:0, 17:1ω8 and 18:1ω7 were predominant.
    [Show full text]
  • Analysis of the Pseudoalteromonas Tunicata Genome Reveals Properties of a Surface-Associated Life Style in the Marine Environment
    Analysis of the Pseudoalteromonas tunicata Genome Reveals Properties of a Surface-Associated Life Style in the Marine Environment Torsten Thomas1*, Flavia F. Evans1, David Schleheck1,3, Anne Mai-Prochnow1,4, Catherine Burke1, Anahit Penesyan1, Doralyn S. Dalisay5, Sacha Stelzer-Braid1,7, Neil Saunders6, Justin Johnson2, Steve Ferriera2, Staffan Kjelleberg1, Suhelen Egan1 1 Centre of Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia, 2 J. Craig Venter Institute, Rockville, Maryland, United States of America, 3 Department of Biology, The University of Konstanz, Konstanz, Germany, 4 Institute of Infection, Immunity and Inflammation, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham, United Kingdom, 5 Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America, 6 School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Australia, 7 Virology Research, Department of Microbiology, South Eastern Area Laboratory Service, Prince of Wales Hospital, Randwick, New South Wales, Australia Abstract Background: Colonisation of sessile eukaryotic host surfaces (e.g. invertebrates and seaweeds) by bacteria is common in the marine environment and is expected to create significant inter-species competition and other interactions. The bacterium Pseudoalteromonas tunicata is a successful competitor on marine surfaces owing primarily to its ability to produce a number of inhibitory molecules. As such P. tunicata has become a model organism for the studies into processes of surface colonisation and eukaryotic host-bacteria interactions. Methodology/Principal Findings: To gain a broader understanding into the adaptation to a surface-associated life-style, we have sequenced and analysed the genome of P.
    [Show full text]
  • Algicidal Bacteria in the Sea and Their Impact on Algal Blooms1
    J. Eukaryot. Microbiol., 51(2), 2004 pp. 139±144 q 2004 by the Society of Protozoologists Algicidal Bacteria in the Sea and their Impact on Algal Blooms1 XAVIER MAYALI and FAROOQ AZAM Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093-0202, USA ABSTRACT. Over the past two decades, many reports have revealed the existence of bacteria capable of killing phytoplankton. These algicidal bacteria sometimes increase in abundance concurrently with the decline of algal blooms, suggesting that they may affect algal bloom dynamics. Here, we synthesize the existing knowledge on algicidal bacteria interactions with marine eukaryotic microalgae. We discuss the effectiveness of the current methods to characterize the algicidal phenotype in an ecosystem context. We brie¯y consider the literature on the phylogenetic identi®cation of algicidal bacteria, their interaction with their algal prey, the characterization of algicidal molecules, and the enumeration of algicidal bacteria during algal blooms. We conclude that, due to limitations of current methods, the evidence for algicidal bacteria causing algal bloom decline is circumstantial. New methods and an ecosystem approach are needed to test hypotheses on the impact of algicidal bacteria in algal bloom dynamics. This will require enlarging the scope of inquiry from its current focus on the potential utility of algicidal bacteria in the control of harmful algal blooms. We suggest conceptualizing bacterial algicidy within the general problem of bacterial regulation of algal community structure in the ocean. Key Words. Algal-killing, Bacillariophyceae, Cytophaga, Dinophyceae, pathogen, phytoplankton, Pseudoalteromonas, Raphidophy- ceae. HE ecological importance of heterotrophic bacteria and there is evidence that certain bacteria specialize in an algicidal T archaea in the ocean is well established, from their uti- life style.
    [Show full text]
  • Biosynthesis and Bioactivity of Prodiginine Analogues in Marine
    Biosynthesis and Bioactivity of Prodiginine Analogues in Marine Bacteria, Pseudoalteromonas: A Mini Review Francis E. Sakai-Kawada1*, Courtney G. Ip2, Kehau A. Hagiwara3, 4, Jonathan D. Awaya1, 2 1Department of Molecular Biosciences and Bioengineering, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, United States, 2Department of Biology, College of Natural 3 and Health Sciences, University of Hawaiʻi at Hilo, United States, Institute of Marine and Environmental Technology, University of Maryland, Baltimore County, United States, 4Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, United States Submitted to Journal: Frontiers in Microbiology Specialty Section: Aquatic Microbiology Article type: Mini Review Article InManuscript review ID: 452936 Received on: 05 Feb 2019 Revised on: 07 Jun 2019 Frontiers website link: www.frontiersin.org Conflict of interest statement The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest Author contribution statement FES and JDA contributed to the conception of the focus for the mini review. FES contributed to the compilation of all sections, figure and table design, and wrote the first draft of the manuscript. CGI contributed to the compilation of biological activity, ecological and evolutionary significance sections. KAH contributed to the biosynthetic pathways and biological activity sections. All authors contributed to manuscript revision, read and approved the submitted version. Keywords Pseudoalteromonas, Prodiginine, Prodigiosin, secondary metabolites, pigments, marine bacteria Abstract Word count: 119 The Prodiginine family consists of primarily red-pigmented tripyrrole secondary metabolites that were first characterized in the Gram-negative bacterial species Serratia marcescens and demonstrates a wide array of biological activities and applications.
    [Show full text]
  • Alteromonas Stellipolaris Sp. Nov., a Novel, Budding, Prosthecate Bacterium from Antarctic Seas, and Emended Description of the Genus Alteromonas
    International Journal of Systematic and Evolutionary Microbiology (2004), 54, 1157–1163 DOI 10.1099/ijs.0.02862-0 Alteromonas stellipolaris sp. nov., a novel, budding, prosthecate bacterium from Antarctic seas, and emended description of the genus Alteromonas Stefanie Van Trappen,1 Tjhing-Lok Tan,2 Jifang Yang,2,3 Joris Mergaert1 and Jean Swings1,4 Correspondence 1Laboratorium voor Microbiologie, Vakgroep Biochemie, Fysiologie en Microbiologie, Universiteit Stefanie Van Trappen Gent, K.L. Ledeganckstr. 35, B-9000 Gent, Belgium [email protected] 2Alfred-Wegener-Institut fu¨r Polar- und Meeresforschung, Bremerhaven, Germany 3Second Institute of Oceanography, Hangzhou, China 4BCCM/LMG Culture Collection, Universiteit Gent, Belgium Seven novel, cold-adapted, strictly aerobic, facultatively oligotrophic strains, isolated from Antarctic sea water, were investigated by using a polyphasic taxonomic approach. The isolates were Gram-negative, chemoheterotrophic, motile, rod-shaped cells that were psychrotolerant and moderately halophilic. Buds were produced on mother and daughter cells and on prosthecae. Prostheca formation was peritrichous and prosthecae could be branched. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains belong to the c-Proteobacteria and are related to the genus Alteromonas, with 98?3 % sequence similarity to Alteromonas macleodii and 98?0% to Alteromonas marina, their nearest phylogenetic neighbours. Whole-cell fatty acid profiles of the isolates were very similar and included C16 : 0, C16 : 1v7c,C17 : 1v8c and C18 : 1v8c as the major fatty acid components. These results support the affiliation of these isolates to the genus Alteromonas. DNA–DNA hybridization results and differences in phenotypic characteristics show that the strains represent a novel species with a DNA G+C content of 43–45 mol%.
    [Show full text]
  • A Novel Screening Method for the Detection of Pseudoalteromonas
    A novel screening method for the detection of Pseudoalteromonas shioyasakiensis, an emerging opportunistic pathogen that caused the mass mortality of juvenile Pacific abalone (Haliotis discus hannai) during a record-breaking heat wave Min Li1, Wenwei Wu1, Weiwei You1, Shixin Huang1, Miaoqin Huang1, Ying Lu1, Xuan Luo1, and Caihuan Ke1 1Xiamen University State Key Laboratory of Marine Environmental Science August 28, 2020 Abstract A serious disease was recorded in juvenile Pacific abalone in Fujian Province, China in 2018. Although this disease caused no obvious external lesions, affected abalone exhibited bleached pedal epithelial cells and a lack of attachment ability. Bacterial strains were collected and cultured from the mucus of moribund and healthy abalone. A novel method was developed for screening abalone pathogens, based on the important role of mucus in the innate immunity of marine organisms. Using bacterial isolation, sequence analysis, and experimental challenges in vitro and in vivo, we identified the bacterial strains pathogenic to abalone. We verified that abalone mortality rates were high when exposed to Pseudoalteromonas shioyasakiensis strain SDCH87 at high temperatures. This opportunistic pathogen had an outstanding growth ability in mucus, and disrupted first line mucosal immunity in the foot within three days. The unprecedented sea surface temperatures associated with the record-breaking 2018 heatwave in south China may have induced opportunistic pathogenic behavior in P. shioyasakiensis. To our knowledge, this is the first report to show that P. shioyasakiensis is a serious opportunistic pathogen of abalone, or possibly mollusks in general, in the context of a heatwave. KEYWORDS Pseudoalteromonasshioyasakiensis ,Haliotis discus hannai , 16s rDNA, mucus resistance, emerging oppor- tunistic pathogen, heat wave 1.
    [Show full text]